Molluscicidal and antiparasitic activity of Solanum nigrum villosum against Galba truncatula infected or uninfected with Fasciola hepatica.

The present study was based on assessments of the molluscicidal and antiparasitic activities of Solanum nigrum villosum. This plant has been collected in Tozeur's traditional oases (south-western Tunisia). Molluscicidal activities of leaves, ripe fruit and unripe fruit extracts of S. n. villosum have been assessed in experimental and semi-field conditions on uninfected Galba truncatula. Antiparasitic activities have also been assessed on larval stages (rediae, intraredial germinal masses and cercariae) of the parasite Fasciola hepatica infecting G. truncatula naturally. The unripe fruit extract (LC50 = 41.2 mg l- 1) was more toxic than the leaf (LC50 = 132.5 mg l- 1) and the ripe fruit (LC50 = 172.8 mg l- 1) extracts on the snail after 48 h of treatment. One mg l- 1 of cupric chloride produced the death of 97% of G. truncatula after 25 days of treatment. Solanum n. villosum extracts used at the lethal laboratory concentration in semi-field conditions were also toxic to G. truncatula. The unripe fruit extract was more toxic than the leaf and the ripe fruit extracts on larval stages of F. hepatica. Maximum deterioration rates were obtained with the unripe fruit extract: 65.6% for rediae, 77.8% for cercariae and 27.6% for intraredial germinal masses after 48 h of treating the snails. The possibility of the unripe fruit extract application for the control of G. truncatula and F. hepatica larval stages should be considered.